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Correspondence  |   September 1997
Area under the Compound A Concentration Curve (Compound A AUC) Analysis
Author Notes
  • Assistant Professor (Bito).
  • Resident (Ikeuchi).
  • Professor and Chairman; Department of Anesthesiology and Intensive Care; Hamamatsu University School of Medicine; Hamamatsu, Japan (Ikeda).
Article Information
Correspondence
Correspondence   |   September 1997
Area under the Compound A Concentration Curve (Compound A AUC) Analysis
Anesthesiology 9 1997, Vol.87, 715-716. doi:
Anesthesiology 9 1997, Vol.87, 715-716. doi:
To the Editor:-We read with interest the article by Kharasch et al. [1] In particular, we found their use of an AUC analysis to quantify compound A exposure to be an interesting approach. We, therefore, re-analyzed the data from our own publication [2] using a similar approach and found the following.
The area under the compound A concentration curve (compound A AUC) was calculated as the product of inspired compound A concentration and duration of exposure, determined at 1-h intervals, using the rhomboid rule. In the low-flow sevoflurane group, the correlations between inspired compound A AUC and both postanesthesia peak NAG and AAP were evaluated.
The mean compound A AUC values in the low- and high-flow sevoflurane groups were 124.4 +/- 66.1 ppm [center dot] h (mean +/- SD; range, 38.4-243.0) and 1.4 +/- 0.6 ppm [center dot] h (0.6-2.5), respectively (P < 0.01). There was no significant correlation between compound A AUC and either postanesthesia peak urinary excretion of NAG or AAP in the low-flow sevoflurane group (Figure 1and Figure 2).
Figure 1. Relationship between postanesthesia peak urinary NAG excretion and compound A exposure (inspired compound A AUC) in the low-flow sevoflurane group (r2= 0.004, P = 0.821).
Figure 1. Relationship between postanesthesia peak urinary NAG excretion and compound A exposure (inspired compound A AUC) in the low-flow sevoflurane group (r2= 0.004, P = 0.821).
Figure 1. Relationship between postanesthesia peak urinary NAG excretion and compound A exposure (inspired compound A AUC) in the low-flow sevoflurane group (r2= 0.004, P = 0.821).
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Figure 2. Relationship between postanesthesia peak urinary AAP excretion and compound A exposure (inspired compound A AUC) in the low-flow sevoflurane group (r2= 0.074, P = 0.313).
Figure 2. Relationship between postanesthesia peak urinary AAP excretion and compound A exposure (inspired compound A AUC) in the low-flow sevoflurane group (r2= 0.074, P = 0.313).
Figure 2. Relationship between postanesthesia peak urinary AAP excretion and compound A exposure (inspired compound A AUC) in the low-flow sevoflurane group (r2= 0.074, P = 0.313).
×
The mean compound A AUC value in the present study was 1.5 times higher than that in the study of Kharasch et al. Nevertheless there was no correlation between inspired compound A AUC and postanesthesia NAG excretion, which is in agreement with the study of Kharasch et al. These data suggest that the exposure dose of compound A was not related to the increase in postanesthesia urinary excretion of NAG or AAP and these increases in NAG and AAP were therefore not due to compound A exposure. These results emphasize that low-flow anesthesia with sevoflurane, in which compound A is formed by the degradation of sevoflurane, does not appear to be associated with renal tubular injury.
Hiromichi Bito, M.D.
Assistant Professor
Yukako Ikeuchi, M.D.
Resident
Kazuyuki Ikeda, M.D., F.R.C.A.
Professor and Chairman
Department of Anesthesiology and Intensive Care; Hamamatsu University School of Medicine; Hamamatsu, Japan
(Accepted for publication May 21, 1997.)
REFERENCES
Kharasch ED, Frink EJ Jr, Zager R, Bowdle TA, Artu A, Nogami WM: Assessment of low-flow sevoflurane and isoflurane effects on renal function using sensitive markers of tubular toxicity. Anesthesiology 1997; 86:238-53.
Bito H, Ikeuchi Y, Ikeda K: Effects of low-flow sevoflurane anesthesia on renal function: comparison with high-flow sevoflurane anesthesia and low-flow isoflurane anesthesia. Anesthesiology 1997; 86:231-7.
Figure 1. Relationship between postanesthesia peak urinary NAG excretion and compound A exposure (inspired compound A AUC) in the low-flow sevoflurane group (r2= 0.004, P = 0.821).
Figure 1. Relationship between postanesthesia peak urinary NAG excretion and compound A exposure (inspired compound A AUC) in the low-flow sevoflurane group (r2= 0.004, P = 0.821).
Figure 1. Relationship between postanesthesia peak urinary NAG excretion and compound A exposure (inspired compound A AUC) in the low-flow sevoflurane group (r2= 0.004, P = 0.821).
×
Figure 2. Relationship between postanesthesia peak urinary AAP excretion and compound A exposure (inspired compound A AUC) in the low-flow sevoflurane group (r2= 0.074, P = 0.313).
Figure 2. Relationship between postanesthesia peak urinary AAP excretion and compound A exposure (inspired compound A AUC) in the low-flow sevoflurane group (r2= 0.074, P = 0.313).
Figure 2. Relationship between postanesthesia peak urinary AAP excretion and compound A exposure (inspired compound A AUC) in the low-flow sevoflurane group (r2= 0.074, P = 0.313).
×